fixed incorrect reporting of unix timestamp; sync time every 12 hours

src/time.cpp

@@ -77,17 +77,19 @@ void uweather_time_handle()
             unsigned long high = word(packet_buffer[40], packet_buffer[41]);
             unsigned long low = word(packet_buffer[42], packet_buffer[43]);
             unsigned long secs = (high << 16 | low) - 2208988800UL; // subtract 70 years from time
-            time_offset = millis();
+            if (has_timestamp()) {
+                Serial.printf("Time Drift: %lu\n", current_timestamp() - secs);
+            }
+            time_offset = millis()/1000;
             ntp_timestamp = secs;
             ntp_state = state::IDLE;
             Serial.printf("Received NTP response, current timestamp is %lu\n", secs);
+            retry_at = millis() +  6 * 60 * 60 * 1000;
         }
         case state::IDLE:
-            break;
-
         case state::NO_HOST:
             if (millis() > retry_at) {
-                state::INIT;
+                ntp_state = state::INIT;
             }
             break;
         default:

src/time.h

@@ -6,5 +6,6 @@ void uweather_time_handle();
 
 unsigned long timestamp(unsigned long);
 unsigned long current_timestamp();
+bool has_timestamp();
 
 #endif /** End _UWEATHER_NTP_H_ include guard */